A man bathes in the Bratmaputra river in Guwahati, Assam. Many Indian states have been affected by drought and water scarcity this year.
Photograph: STR/EPA

Nigeria

In the displacement camps of north-east Nigeria, most residents have the same answer for why 2.6 million people have been forced from their homes in this region. They are running from Boko Haram, the jihadist militants who still control significant parts of the Lake Chad basin.

But ask about how Boko Haram gained momentum in the first place, and a more complex narrative emerges. The extremists capitalised on high levels of local poverty, alienation and unemployment in north-east Nigeria. And that in turn, many local residents argue, was fuelled – in part – by the shrinking of Lake Chad, and the desertification of the surrounding area. With global temperatures soaring ever higher, it’s a trend unlikely to be reversed any time soon.

“It’s affected our livelihood, it’s affected farming and fishing,” says Mustapha Ali, a 50-year-old who grew up close to the lake’s former shores, and who is now living in a camp for internally displaced people. “We used to farm watermelon here, wheat, and rice – but because of the shrinkage of the lake, we can’t any more. Little by little it became harder and harder to [irrigate the] farm.”

Women arrive in a camp in the village of Kidjendi after fleeing from Boko Haram attacks. Photograph: Issouf Sanogo/AFP/Getty Images

Since the 1970s, global warming has caused the lake to shrink by around 90%. Once one of the world’s biggest lakes, at 25,000 sq km, it is now less than 2,500 sq km. Towns that Ali remembers reaching by boat can now be reached by car. At least one settlement has even been built on land that used to be underwater, Ali says.

For residents like Ali, the desperation caused by the shrinking of the lake was clearly a contributing factor to the rise of extremism.

“It’s helped the rise of Boko Haram,” Ali adds. “A lot of the youth there were unemployed, and when they have nothing to do, Boko Haram becomes an option. If you’re wealthy and you have things to do, you don’t want things like [Boko Haram] to happen.” Patrick Kingsley at Lake Chad

US

The Iditarod Trail Sled dog race is a fabled 1,000-mile-long trek through Alaska’s frozen wilderness, held annually since 1967. Unusually warm weather prompted a change in the starting location for last year’s race, while 7,000 gallons of snow was shipped in ahead of this year’s event in case of a lack of powder. The race, held in March, followed Alaska’s second warmest winter on record – the latest in a string of warm winters.

Chas St George, chief operations officer at the Iditarod trail committee, said: “You have ups and downs in terms of snow but this year and the year before were very mild in terms of weather and snowfall. Our creeks are flowing earlier and we are also getting more sun, which provides its own challenge for the people racing.

“Last year we staged the race out of Fairbanks because of a lack of snow, which is quite a distance further north. It’s cooler there, there’s more snow. We’ve only been forced to do that kind of thing in the last few years. There are times when these teams run on no snow at all. The question is whether you have enough snow at the start, until you get to the interior.

The ceremonial start of the course in Anchorage, Alaska, had to be shortened due to lack of snow. Photograph: Alamy Stock Photo

“This year for the ceremonial start, where people come out to watch the teams through Anchorage, we had to shorten the course from 11 miles to three miles. That was for safety reasons because there was only enough snow to get to a certain point. We haven’t had to shorten the course like that before.

“When it thaws and then freezes, all what’s left is ground that is still frozen, it’s very slick ice. It becomes a safety issue. People want to go as far as they can, that’s what they do this for, but they were very understanding. I’m sure the dogs were disappointed.

“We did have a contingency to get more snow in by rail this past year. It wasn’t needed though, we had enough snow, thank goodness. In parts of the course there was very little snow and then suddenly a huge amount of it hit.

“In Alaska there’s a ton of research that shows we are sort of at ground zero here [for climate change]. There’s been a clear warming trend. I don’t see significant changes to the race in the next couple of years but over the next 20 to 30 years we might have to look at it through a different lens. We may have to do things differently. But we want to keep this tradition going.” Oliver Milman in New York

Russia

Rodion Sulyandziga of the Center for Support of Indigenous Peoples of the North. Photograph: Courtesy of Rodion Sulyandziga

Rodion Sulyandziga, who runs the Moscow-based Center for Support of Indigenous Peoples of the North, says climate change is now one of the key challenges facing Siberia’s numerous indigenous communities.

Many ordinary Russians laugh at the idea of global warming as a threat, pointing out that much of the country would benefit from warmer temperatures. But melting permafrost could create real problems for communities in the far north of the country.

“Climate change is already here and is already affecting the lives of most of the indigenous community populations in the far north and Siberia, in various different ways,” said Sulyandziga.

The dangers were brought into sharp focus earlier this year when an anthrax outbreak hit the Yamal peninsula which killed a child, left 23 people dead and also killed more than 2,000 reindeer. The Arctic region is mainly populated by nomadic reindeer herders. There have been discussions about reducing the reindeer population to insure against future outbreaks, with radical suggestions including culling 200,000 animals.

The working hypothesis for the deaths is that the infection was started when the corpses of reindeer that died many years ago were uncovered due to melting permafrost. This summer was abnormally warm in Yamal.

“At a governmental level, it’s really important that Russia ratifies the Paris agreement and gets to work on developing a national strategy,” said Sulyandziga. “But we are also trying to work on strategies in each region, and make sure local indigenous communities are involved, to help protect these traditional ways of life.”

Sulyandziga’s centre works to ensure representatives of the communities themselves also have a say in discussions with authorities on how to mitigate the consequences of climate change. Fighting for indigenous rights is not always easy in Russia: Sulyandziga has been, on various occasions, fined, banned from leaving the country, and forced to declare his organisation a “foreign agent”. Shaun Walker in Moscow

India

In the town of Phalodi, surrounded by the Rajasthani deserts of western India, the mercury hit 51C in May, the highest recorded temperature in Asia since 1956. As a result, people generally stopped working during the main heat of the day.

Firoz Khan: ‘It was difficult even to leave the house.’ Photograph: Vidhi Doshi

Firoz Khan, a nurse in the local hospital recalls that life in the village came to a standstill. “It was difficult even to leave the house,” he said. “Everyone was fretting.”

The 100,000 residents of Phalodi are used to extreme heat in the summers, but this year was exceptionally bad, and the normal working routine was disrupted. “It was very, very hot. You’d start sweating if you stepped out of your house,” Khan recalled.

“In fact, most people only worked in the mornings, from dawn until 10-11am, and then they’d have to stay in all day because of the heat. Then around 5-6pm, people would leave home again and do a few more hours of work. Farmers lost around half their crop because of the heat this year. But at the time, they didn’t care. They just wanted to sit indoors, under the fan or air conditioner.”

At the hospital where he works, Khan saw dozens of people coming in with heatstroke. “They just couldn’t take it. People were vomiting, they were suffering from diarrhoea or dysentery, and they were finding it difficult to urinate. A handful of people from the town died because of the heat. They were older people, including a couple of women. For others, it was too hot, even to leave home to come to the hospital.”

Families sleep on the roof of their homes as temperatures soar in Varanasi, India. Photograph: Yasmin Mund / Barcroft Media

Schools were forced to close down, or send children home after a few hours of study, at 11am.

In the surrounding villages water shortages devastated crops. “There was enough water to drink from the rainwater harvesting tanks, but those who rear animals really suffered because there wasn’t enough water for them,” said Khan. Vidhi Doshi in Mumbai

Finland

French winemakers joke about harvesting grapes on skis. But Fredrik Slotte, 36, who has 850 vines on his farm in Finland, has the last laugh.

Last autumn at a festival in the US his sparkling wines won a gold medal, beating competition from 2,000 wines from 12 countries, including French champagne.

“It is great to see that Finland can compete in blind tastings with France,” Slotte said.

This summer has been a particularly good one for grapes on the Baltic island of Åland, where Slotte has his vineyard. The spring came early, and there was no frost. May was very warm, so the flowering started quickly in June.

“We got a long period from the flowering to the harvest, and it was very dry,” Slotte said. “During the maturing process I want the grapes to be as concentrated as possible, and every drop of rain dilutes my wine and risks mould.”

Slotte has been growing grapes in Finland since 1998, when everyone thought he was “crazy”. But with an embryonic commercial wine industry in neighbouring Sweden and Denmark, no one thinks that any more.

Swedish winegrowers say that, thanks to climate change, they now have an extra month in the growing season each summer compared to 40 years ago, when the Septembers were not as warm as they are today. Some growers can even harvest their grapes at the end of August.

Ironically, while his grapes did well this year, Slotte was hit because he also grows wheat, which suffered from the heat and dryness. But he is expecting a good vintage from 2016.

“There are a lot of factors in making good wine, not just climate change,” he said. “But if you want a deep style with a lot of body, you want a good year like this.” David Crouch in Gothenburg

Thailand

Thailand suffered its worst drought in two decades this year, focused in the country’s arid north-east where reservoirs are at record low levels.

Arkom Kammag, 37, grows figs and raspberries for a family business in Nakhon Ratchasima, one of the worst-hit provinces. The rainy season brought some relief this year but just ended, he said, and it started late. During the toughest months, mud – not water – was coming out of the taps.

“Trees were drying up and some grew really, really slowly,” he said. “It’s difficult to live in this kind of hot and dry weather.”

Kammag and his family used to stock up on fresh rainwater to drink but for the first time they’ve had to buy it. Resorting to underground wells after surface water dried up, he also ran an expensive pump for eight hours a day. Many farmers have been pushed into debt.

The world’s second-largest sugar and rice exporter, Thailand saw a cut in production for both crops after four consecutive years of below-average rainfall. The government has spent more than £500m to help farmers.